Subsea button-type electrical connector

ABSTRACT

A multi-conductor electrical connector means for use in an adverse hostile environment such as a subsea installation, the connector means including a plurality of connector members and connector elements providing electrical connections for a plurality of circuits. Each connector member carried in a plug means is individually, separately adjustable to provide an effective electrical contact with its associated connector element to compensate for metal deformations in contacting surfaces under constant high pressures required in such hostile environment and to provide for the making and breaking of repeated electrical connections as may be required during installation and maintenance. A plug means for an electrical connector means in which an elongated contact member is nonrotatably advanced by a rotatable driven follower member.

United States Patent [191 Falkner SUBSEA BUTTON-TYPE ELECTRICALCONNECTOR Chester B. Falkner, Whittier, Calif.

[73] Assignee: Deep Oil Technology Inc., Long Beach, Calif.

22 Filed: Nov. 24, 1972 21 Appl. No.: 309,416

[75] Inventor:

[52] 1.1.8. Cl. 339/75 M, 339/96, 339/94 M [51] Int.'Cl. H0lr 13/54,H0lr 9/06 [58] Field of Search 339/31, 60, 94 R, 94 M,

339/143, 149 P, 150 B, 34, 35, ZOO-202, l8, 96, 75 R, 75 M, 75 P [56]References Cited UNITED STATES PATENTS 2,163,201 6/1939 Kalencik 339/31M 2,620,029 12/1952 Turechek et al 339/96 2,703,870 3/1955 Minto 339/94M 2,782,275 2/1957 Vance.... 339/18 C X 2,877,324 3/1959 Oshry 200/159 BUX 3,025,486 3/1962 Falconer.... 339/31 R 3,058,086 10/1962 Zwanzig339/94 R Nov. 19, 1974 3,571,779 3/1971 Collier 339/18 C PrimaryExaminer-Roy D. Frazier Assistant Examiner-Lawrence J. Staab Attorney,Agent, or Firm-Edward F. Jaros [57] ABSTRACT A multi-conductorelectrical connector means for use in an adverse hostile environmentsuch as a subsea installation, the connector means including a pluralityof connector members and connector elements providing electricalconnections for a plurality of circuits. Each connector member carriedin a plug means is individually, separately adjustable to provide aneffective electrical contact with its associated connector element tocompensate for metal deformations in contacting surfaces under constanthigh pressures required in such hostile environment and to provide forthe making and breaking of repeated electrical connections as may berequired during installation and maintenance. A plug 4 means for anelectrical connector means in which an elongated contact member isnon-rotatably advanced by a rotatable driven follower member.

6 Claims, 5 Drawing Figures PATENTED HO 1 9 3.848.949

sum 1 or 2 PATENTEL HEY I SIB" SHEEI 2 OF 2 BACKGROUND OF INVENTIONElectrical connections made under conditions of hostile adverseenvironment such as connecting to a subsea wellhead or productioncontrol unit located at a sea floor, require relatively high pressuresto maintain effective electrical contact under sealing conditionsrequired to isolate the electrical contacting surfaces from the adverseenvironment. During installation and also during later maintenance ofelectrical connections at suchwell equipment, the electrical connectormay be repeatedly connected and reconnected. Each time an electricalconnection is made, electrical conducting contact surfaces of the metalconductors become deformed, particularly when one of the conductors maybe of a softer metal relative to that of the other conductor. Within thephysical limits of relative displacement of the connector receptacle andplug bodies of prior proposed sealed electrical connectors, deformationof the contacting metal of the cooperable conductor members rapidlyreaches an unsatisfactory electricalcontacting condition and such metalto metal contact is not correctable by further tightening of thereceptacle and plug members of the connector means.

Prior proposed subsea electrical connectors for use in such hostileenvironment are disclosed in U.S. Pat. Nos. 2,700,141 2,703,870, and3,657,681. In U.S. Pat. No. 2,700,141 movable and fixed electriccontacts and puncturable discs or gaskets containing a sealing compoundare carried in a pair of water tight separable members, the movablecontacts puncturing and moving through the discs to make electricalconnection with the fixed contacts. In U.S. Pat. No. 2,703,870connectingpins penetrated discs of soft rubber having convex opposed faces toexpel fluid from the space between said convex surfaces to protect thecontact elements from the fluid. In my patent, U.S. Pat. No. 3,657,681fluid was purged between opposed annular contact elements carried inexposed position on convex resilient surfaces. In application Ser. No.197,324 filed Nov. 10, 1971 (owned by a common assignee) an electricalconnector means is disclosed in which button-type contact members areused and protected with an elastomeric material which may be penetratedby one of the contact members upon drawing the receptacle and plugmembers together. In said application shim means are provided betweenthe receptacle and plug members to regulate depth of penetration andduring repeated coupling and uncoupling of the connector means, shimsmay be withdrawn to permit increased penetration of one conductor memberwith the other conductor member to assure effective electrical contact.

ln each of such prior proposed'electrical connector means, after aseries of repeated connections have been made, some of the electricalcontacts maybe satisfactory and others may not be satisfactory. Thus theentire electrical connector means may require replacement.

to provide uniform advancement and pressure of the circularly arrangedcontact elements, acceptable tolerances between the two mating housingportions often permitted non-uniform pressure engagement between thecontact members with the result that circuits on one side may besatisfactorily completed while circuits on the opposite side were notsatisfactorily in desired electrical contact. Such difference inpressure engagement about circularly arranged contact members becameincreasingly evident after several electrical connections had been made.

SUMMARY OF THE INVENTION This invention relates to an electricalconnector means particularly adapted for use in a subsea hostileenvironment and so constructed and arranged as to avoid disadvantages ofprior proposed constructions and to provide positive precise electricalcontact between contact members. The invention particularly relates toan electrical connector means wherein each contact member carried by aplug means is individually and separately axially movable into desiredpressure contact with its corresponding contact element carried by areceptacle means, the pressure contact being determined by thedisplacement of'the contact member rather than by the assembly underpressure of the plug and receptacle means.

An object of the present invention is to disclose a novel constructionof a subsea electrical connector means of button-type wherein positiveeffective electri plurality of contacts and arranged to provideeffective repeated electrical contact between v cooperable contactmembers.

An object of the invention is to disclose an electrical connector meanswherein electrical contact between axially opposed contact members andelements is obtained by separate individual adjustment of one of thecontact members.

Another object of the present invention is to disclose and provide anovel means for axially displacing or advancing one of the contactmembers to provide an effective electrical contact with an opposedcontact element.

A further object of the invention is to disclose a plug means for anelectrical connector wherein contact members are individually andseparately advanced, each by a rotatable follower member selectivelyadjustably turned through means external of the connector means.

A still further object of the present invention is to disclose a novelconstruction of a plug means for an electrical connector wherein saidplug means includes cap means carrying a plurality of follower membershaving contact at their inner ends with electrical contact members.

A still further object of the invention is to disclose and provide aplug means for an electrical connector means wherein said plug meansincludes means to advance electrical contact members without rotationthereof.

Generally speaking, the present invention contemplates a receptaclemeans having a chamber within which is supported a plurality of contactelements wrench advances the associated contact member through theprotective covers into selected pressure contact with the contactelements to achieve desired electrical metal to metal surface contactbetween the contact member and contact element.

Various other objects and advantages of the present invention will bereadily apparent from the following description of the drawings in whichan exemplary embodiment of th invention is shown.

IN THE DRAWINGS FIG. 1 is a side elevational view, partly insection, ofan electrical connector embodying this invention, said section beingtaken in a longitudinal plane passing through the axis of the connectorand through a support wall, one of the contact members being shown innormal retracted or initially assembled position and the other contactmember being shown in projected or advanced position for makingelectrical contact with a contact element.

FIG. 2 is a view taken from the vertical plane indicated by line Il-Ilof FIG. 1, FIG. 2 being partly in section and showing a cable connectionto the electrical connector.

FIG. 3 is a fragmentary sectional view taken in the vertical planeindicated by line IIIIII of FIG. 1.

FIG. 4 is a fragmentary vertical sectional view taken in the planeindicated by line IVIV of FIG. 1.

FIG. 5 is a fragmentary vertical sectional view taken in the planeindicated by line V-V of FIG. 1.

An electrical connector generally indicated at embodying this inventionis shown in FIG. 1. Generally, connector means 10 includes a receptaclemeans 11 which cooperably receives a plug means 12 in such relation thatfluid is purged from the connection and electrical contact of theelectrical conducting elements is made under protected conditions.Receptacle means 11 may be suitably mounted on a wall 14 which may be awall of a subsea wellhead unit, a subsea production control unit, or abulkhead. An electrical cable 15 extends through a suitable weather andseal tight fitting 16 in wall 14 for connection to receptacle means 11.An electrical cable 17 is connected to plug means 12 as described indetail later. It will be understood that the cables 15 and 17 may be ofany suitable construction for use in a hostile environment and thatvarious forms of entrance connections to the receptacle means and theplug means may be utilized.

Receptacle means 11 is of a construction similar to the correspondingreceptacle or housing portion of said copending application Ser. No.197,324. Receptacle means 11 provides a stepped chamber means includingan outer chamber 20, an intermediate chamber 21 of reduced diameter andlocated interiorly of outer chamber 20, and an inner still furtherreduced diameter chamber 22 forming with chamber 21' an annular shoulder23. Inner chamber 22 communicates with fitting 16 for cable 15.Receptacle means 11 may be made of any suitable material for examplemetal, to

provide a housing capable of withstanding pressures of the hostileenvironment. Receptacle means 11 includes on its back face an annularseal means 24 seated against the exterior surface of wall 14 andsuitably secured by bolts 25.

Cable wires 27 from cable 15 are provided with an electrical connectionat 28 in chamber 22 with contact elements 29 provided in a compositecontact carrier member 30 located in chamber 21 and seated againstshoulder 23. Carrier member 30 includes a hard nondeformable dielectricbase portion 31-of water resistant material such as a hard neoprene ormicarta material.

Base portion 31 carries seal means 32 for sealing engagement with sidewalls of chamber 21. Base portion 31 is also provided with a location orregistration pin 33 receivable within aligned bores in base portion 31and in receptacle means 11.

Carrier member 21 also includes a top portion 35 of relatively softresilient dielectric material such as a soft neoprene. The top portion35 is seated and bonded against the outwardly facing surface of the baseportion 31 and completely imbeds the cylindrical heads 36 of connectorelements 29. Connector heads 36 have an inwardly facing shoulder seatedagainst base portion 31 and shank portions 37 extend through baseportion 31 for the electrical connection at 28. The soft resilientportion 35 serves as a protective cover for. the connector elements 29,each outwardly directed contacting face 38 of each contactor head 36being protected by a selected thickness of the resilient dielectricmaterial and forms thereover an embossment which appears as a button.

The contactor elements 29 may be arranged in any suitable preselectedpattern, in this example a generally circular pattern with a contactorelement also located at the center of the circle. The registration pin33 extending into aligned bores in the receptacle body and the carriermember 31 precisely orients the contact elements 29 with respect to thereceptacle means 11.

Receptacle means 11 includes a'longitudinally extending slot 40 at itsopen end for reception of an alignment pin 41 carried by plug means 12to orient the plug means with respect to the receptacle means 11.Receptacle means 11 also carries a plurality of circumferentiallyarranged securement bolts 42 provided with internal cam faces for camengagement with an annular groove 43 in the outer cylindrical surface ofplug means 12, said groove 43 being generally V shaped in section sothat as bolts 42 are tightened the plug means 12 will be urged inwardlyof the receptacle means 11.

The above-described receptacle means 11 and cooperable engagement of aplug means with such a recep tacle'means is described in copendingapplication Ser. No. 197,324.

The present invention relates to the construction and operation of plugmeans 12 in association with receptacle means 11. Plug means 12 maycomprise a generally cylindrical connector body having an open end 51with an internal radially inwardly extending flange 52 provided with aforwardly directed annular seat 53 for seating a carrier body 54.Carrier body 54 is made of dielectric material similar to that ofcarrier member 30 and includes a relatively hard base portion 55 and arelatively soft resilient portion 56. Carrier body 54 snugly fits withinopen end 51 and may be provided with an O-ring seal means 57, carriermember 31 and carrier body 54 being of the same diameter andpositionable the corresponding button contact areas on the carriermember 31.

Base portion 55 of carrier body 54 is provided with a plurality ofcircularly arranged and central through bores 61 of uniform diameter.Each through bore 61 slidably carries a contact member 63 provided withO- ring type seal means 64 for sealing engagement with through bore 61.Each contact member 63 includes an enlarged head 65 having an enlargedcylindrical portion 66 providing an annular shoulder for seatingengagement as at 67 against base portion 55. Each head 65 includes aconical portion 68 having a pointed contact end protectively covered bya button portion of resilient material 56.

Means for individually and separately advancing each contact member 63through resilient portion-56 and into electrical contact with itsrespective contact element on the receptacle means may comprise anelongated shank portion 70 on each'contact member 63, shank portion 70extending rearwardly beyond flange 52 and into a rearwardly facingchamber 71 formed in plug means 12. Within chamber 71 is provided afollower member 72 for each contact member 63. Each follower member 72includes a cylindrical body 74 of larger diameter than shank portion 70to provide at its inner end an end facing recess 75 within which isreceived the outwardly directed end 78 of the shank portion 70. Betweenwalls of recess 75 and end 78 is a cup-shaped insert 76 of dielectricmaterial to provide electrical insulation and at the bottom of thecup-shaped insert is a washer 77 to provide bearing contact with end 78of shank portion 70. Such bearing contact permits rotation of followermember 72 with respect to shank portion 70 as later described.

Means for supporting the follower members 72 in axial alignment withtheir respective contact member 63 may comprise a cap means 73 having abody portion 80 received within said chamber 71 and having an externalflange means 81 seated on the end face of carrier body 50 as at 82 andsecured thereto by headed screw bolts 83. Cap body 80 is provided with aplurality of follower bores 85, each follower bore 85 having a boreportion 86 adapted to receive follower member 72 in sliding rotatablerelation. Seal means comprisinga pair of spaced O-rings 87 carried ineach follower member provides a seal at each follower between chamber71" and the environment exterior to cap means 73. Bore 85 includes anouter section 88 of slightly reduceddiameter than section 86 to providea shoulder 89 affording a stop for follower 72 when moved in an outwarddirection.

Each follower member .72 includes an externally threaded portion 90which engages internal threads as at 91 provided in the reduced boresection 88. Outwardly of threaded portion 90 each follower member 72 isprovided with a wrench engaging end portion 92 of suitable polygonalsection and adapted to receive a socket on a socket wrench for turningthereof. Socket engaging ends 92 of each follower member are located ina circular recess 93 defined by an axially extending annular flange 94formed on cap means 73, said flange 94 protecting the socket engagementends 92 of the follower members.

Each follower member 72 may thus be engaged by a socket wrench androtated whereby the follower member is axially moved to advance contactmember 63 associated therewith towards its mating contact element andinto selected pressure engagement therewith. Means to prevent rotationof each contact member 63 includes an elongated flatted recess 96provided in shank portion adjacent the face of base portion 54.Receivable within each flatted recess 96 may be a fixed lug member 97secured to base portion 54 by a suitable screw bolt 98. Turning ofcontact member 63 is thereby prevented and entanglement of electricalleads 100 connected to said contact member 63 at 101 is therebyprevented.

Means for entry of electric leads 100 to chamber 71 from cable 17 isbest shown in FIG. 2 wherein a cable fitting includes a side outlet body111 secured against a flatted surface 112 of cylindrical body 50 and atan entrance opening 113 formed therein. Internal cable 114 extendsthrough an internal cable socket 115 and through suitable bushing sealmeans generally indicated at 116 of suitable make and manufacture forproviding a sealed entrance into chamber 71. The other end ofintermediate cable 114 is encapsulated in a suitable dielectric block118 where connections 119 are made to cable lines 120 provided in cable17. Cable lines 120 extend through another dielectric body 121 and bothdielectric bodies 121 and 118 are protectively housed within a rigidcable socket member 122 having external threads 123 for sealingengagement with internal threads 124 provided on an attachment fitting125. Attachment fitting 125 is secured by. screw bolts 126 to sideoutlet body 111. It should be noted that the inner end of attachmentfitting 125 is provided with a conical face 128 extending beyond thesecurement lugs 129 and having O-ring type seals for pressure sealingengagement with an outwardly flared face 130 provided by the side outlet111. Thus a suitable side connection is provided for cable 17 to thecontact members within the plug means 12, such side entry permittingexposure of the socket engagement portions 92 of the follower members sothat access thereto for turning is readily provided.

In installation of a connector means 10 described above, receptaclemeans 11 is securedto a supporting structure such as wall 14 in wellknown manner. Plug means 12 with each connector member 63 is retractedposition is then inserted into the chamber 20 of receptacle means 11 inproper alignment as determined by registration pin 41 and slot 40.Securement bolts 42 are then sequentially tightened in a pre-selectedorder so as to substantially uniformly advance plug means 12 and theresilient portion 56 into pressure engagement with the opposed buttonresilient portion 35 of the receptacle means. Upon such pressureengagement of the button contacting faces, it will be apparent thatfluid is purged from between said faces and is displaced into theannular space 132 between opposed end faces of the carrier means 30 and54. Excess fluid flows through the annular passageway 133 providedbetween the interior walls of chamber 20 of the receptacle means andexternal walls of the plug means 12, such passageway being provided byrelatively loose clearance between the plug means 12 and the receptaclemeans 11. After the securement bolts 42 have been tightened so that theplug means 12 is in a selected initial position, each connector member63 is then axially advanced by rotation of follower members 72 and bymeans of a socket wrench engaging the engagement portion 92 on thefollower members. The conical head 68 on each connector member 63pierces in pressure sealing engagement the protective covers between theconical head 68 and the opposed face of connector element 29. Desiredelectrical contact is determined by any suitable electrical measuringinstrument. Thus initial proper electrical contact of each connectormember and connector element is assured.

The connector means 10 may be disconnected by withdrawal of securementbolts 42 and upon withdrawal of the plug means 12 from the receptaclemeans 11 the protective covers over contact elements 29 tend to selfseal upon such withdrawal of each conical head.

of the pressure engagement thereof. In the event the relatively softcontactor element becomes deformed at the point of contact with theconical connector head 68 as indicated by electrical testing, thefollower element may be further tightened to axially drive the connectormembers 63 into further pressure engagement with connector element 29.

i It will be understood that deformation of the contacting surfaces onconnector elements 29 may vary for each connector element and that suchvariation is readily compensated for by the individual adjustment ofeach conductor member 63. Repetitive making and breaking of electricalcontact between connector member 63 and connector elements 29 maycontinue until the connector member 63 can no longer be advanced intodesired pressure engagement and as restricted by the length of the slot96 therein. It will be apparent from the construction of the plug means12 that when such condition occurs disassembly of the carrier body 54from the connector body 50 is readily accomplished by removing cap means73, unloosening the carrier body securement screws and withdrawing thecarrier body with the connector members 63 from the plug means 12.

It will be understood that various modifications and changes may be madein the construction and operation of the plug means 12 described aboveand all such changes and modifications come within the scope of r theappended claims are embraced hereby.

I claim:

I. In a multi-contact button-type electrical connector for use in ahostile environment, the combination of:

a receptacle means provided with a chamber having an open end;

a carrier member within said chamber provided with a plurality ofcontact elements having a resilient protective cover thereover;

a plug means receivable within said open end and chamber of saidreceptacle means;

a carrier body carried by said plug means in alignment with said carriermember on said receptacle means,

said carrier body including a plurality of through bores,

a contact member slidable in each through bore and having a pointedcontact head aligned with a 5 contact element in said receptacle means,

a protective cover embedding said pointed head and adapted to contactthe cover on said contact element;

and means for individually and separately advancing each contact memberinto a selected electrical contact with its respective contact element;

said last mentioned means including a follower member having an innerend in force applying relation to an end of a contact member,

said follower member having an outer end having means for receivingforces to move said follower member and said contact member axially intoelectrical contact with said contact element.

2. In a multi-contact button-type electrical connector for use in ahostile environment, the combination of:

a receptaclemeans provided with a chamber having an open end;

a carrier member within said chamber provided with a plurality ofcontact elements having a resilient protective cover thereover;

a plug means receivable within said open end and chamber of saidreceptacle means;

a cap means for saidplug means;

a carrier body carried by said plug means in alignment with said carriermember on said receptacle means,

said carrier body including a plurality of through bores,

a contact member slidable in each through bore and having a pointedcontact head aligned with a contact element in said receptacle means,

said cap means including a follower bore for each contact member;

a protective cover embedding said pointed head and adapted to contactthe cover on said contact element;

and means for individually and separately advancing each contact memberinto a selected electrical contact with its respective contact element;

said separately advancing means including a follower member extendingthrough said follower bore into engagement with its respective contactmember and operable externally of said plug means;

and means interconnecting said follower member and contact member forpermitting relative rotation therebetween during axial movement of saidcontact member.

3. In a multi-contact button-type electrical connector for use in ahostile environment, the combination of:

a receptacle means provided with a chamber having an open end;

a carrier member within said chamber provided with a plurality ofcontact elements having a resilient protective cover thereover;

a plug means receivable within said open end and chamber of saidreceptacle means; a cap means for said plug means; a carrier bodycarried by said plug means in alignment with said carrier member on saidreceptacle means, said carrier body including a plurality of throughbores,

a contact member slidable in each through bore and having a pointedcontact head aligned with a contact element in said receptacle means,

said cap means including a follower bore for each contact member,

a protective cover embedding said pointed head and adapted to contactthe cover on said contact element;

and means for individually and separately advancing each contact memberinto a selected electrical contact with its respective contact element;

said separately advancing means including a follower member extendingthrough said follower bore into engagement with its respective contactmember and operable externally of said plug means;

and means for limiting rotation of each of said contact members duringaxial movement thereof,

means in fixed relative non-rotational assembly, opposing faces of thecontact element and contact member being in spaced relationship, andprotective cover means between said opposing faces, the improvementcomprising:

means to restrict said internal contact member to non-rotational axialmovement; and a rotatable follower member carried by the plug means andhaving an inner end aligned with one end of the contact member and anouter end external of said plug means, said inner end having meansforreceiving the adjacent end of the contact member for relative rotationtherebetween during longitudinal movement of the follower member and thecontact member into electrical contact with the contact element, anddielectric means within said inner end receiving means for electricallyinsulating said follower member from said contact member. 5. In anelectrical connector as stated in claim 4 wherein a recess is providedin the end of said follower member, and cup-shaped dielectric means inthe recess receive the end of the contact member. 6. In a connector asstated in claim 5 including a thrust bearing washer in said cup-shapeddielectric means for bearing engagement with the end of the contactmember received in said recess.

1. In a multi-contact button-type electrical connector for use in ahostile environment, the combination of: a receptacle means providedwith a chamber having an open end; a carrier member within said chamberprovided with a plurality of contact elements having a resilientprotective cover thereover; a plug means receivable within said open endand chamber of said receptacle means; a carrier body carried by saidplug means in alignment with said carrier member on said receptaclemeans, said carrier body including a plurality of through bores, acontact member slidable in each through bore and having a pointedcontact head aligned with a contact element in said receptacle means, aprotective cover embedding said pointed head and adapted to contact thecover on said contact element; and means for individually and separatelyadvancing each contact member into a selected electrical contact withits respective contact element; said last mentioned means including afollower member having an inner end in force applying relation to an endof a contact member, said follower member having an outer end havingmeans for receiving forces to move said follower member and said contactmember axially into electrical contact with said contact element.
 2. Ina multi-contact button-type electrical connector for use in a hostileenvironment, the combination of: a receptacle means provided with achamber having an open end; a carrier member within said chamberprovided with a plurality of contact elements having a resilientprotective cover thereover; a plug means receivable within said open endand chamber of said receptacle means; a cap means for said plug means; acarrier body carried by said plug means in alignment with said carriermember on said receptacle means, said carrier body including a pluralityof through bores, a contact member slidable in each through bore andhaving a pointed contact head aligned with a contact element in saidreceptacle means, said cap means including a follower bore for eachcontact member; a protective cover embedding said pointed head andadapted to contact the cover on said contact element; and means forindividually and separately advancing each contact member into aselected electrical contact with its respective contact element; saidseparately advancing means including a follower member extending throughsaid follower bore into engagement with its respective contact memberand operable externally of said plug means; and means interconnectingsaid follower member and contact member for permitting relative rotationtherebetween during axial movement of said contact member.
 3. In amulti-contact button-type electrical connector for use in a hostileenvironment, the combination of: a receptacle means provided with achamber having an open end; a carrier member within said chamberprovided with a plurality of contact elements having a resilientprotective cover thereover; a plug means receivable within said open endand chamber of said receptacle means; a cap means for said plug means; acarrier body carried by said plug means in alignment with said carriermember on said receptacle means, said carrier body including a pluralityof through bores, a contact member slidable in each through bore andhaving a pointed contact head aligned with a contact element in saidreceptacle means, said cap means including a follower bore for eachcontact member, a prOtective cover embedding said pointed head andadapted to contact the cover on said contact element; and means forindividually and separately advancing each contact member into aselected electrical contact with its respective contact element; saidseparately advancing means including a follower member extending throughsaid follower bore into engagement with its respective contact memberand operable externally of said plug means; and means for limitingrotation of each of said contact members during axial movement thereof,said follower members having threaded engagement with said cap means foraxial movement of said follower member to drive said contact member intoselected depth of penetration of said contact element for makingelectrical contact of desired characteristics.
 4. In an electricalconnector for use in a hostile environment and including a receptaclemeans having an internal contact element, a plug means having aninternal contact member alignable with the contact element, means forholding said receptacle and plug means in fixed relative non-rotationalassembly, opposing faces of the contact element and contact member beingin spaced relationship, and protective cover means between said opposingfaces, the improvement comprising: means to restrict said internalcontact member to non-rotational axial movement; and a rotatablefollower member carried by the plug means and having an inner endaligned with one end of the contact member and an outer end external ofsaid plug means, said inner end having means for receiving the adjacentend of the contact member for relative rotation therebetween duringlongitudinal movement of the follower member and the contact member intoelectrical contact with the contact element, and dielectric means withinsaid inner end receiving means for electrically insulating said followermember from said contact member.
 5. In an electrical connector as statedin claim 4 wherein a recess is provided in the end of said followermember, and cup-shaped dielectric means in the recess receive the end ofthe contact member.
 6. In a connector as stated in claim 5 including athrust bearing washer in said cup-shaped dielectric means for bearingengagement with the end of the contact member received in said recess.